**Learning Objective:**

**What does Kurtosis relate to?****How to measure Kurtosis?**

**Concept:**

**Kurtosis relates to bulginess, peakedness, tailedness of a frequency distribution.****Leptokurtic frequency distribution is narrow with sharp peak and extended tails.****Mesokurtic frequency distribution is normal with less sharp peak and not much extended tails.****Platykurtic frequency distribution is like platypus without sharp peak and very less extended tails.****Kurtosis is measured with Pearsonian's Coefficient of Kurtosis which is based on central moments.****If γ₂ > 0, the frequency distribution is Leptokutic.****If γ₂ = 0, the frequency distribution is Mesokurtic.****If γ₂ < 0, the frequency distribution is Platukurtic.**

**Formulas:**

**Pearsonian's Coefficient of Kurtosis**

**β₂ = μ₄ / μ₂²****γ₂ = (β₂ - 3)**

Pearson kurtosis does not measure sharpness or flatness at all. You can have very low Pearson kurtosis for an infinitely peaked distribution, and you can have a very high Pearson kurtosis for a perfectly flat-topped distribution. Pearson kurtosis only measures tail weight.